Goofy fun, in fact, is a big reason the original flick became an unexpected blockbuster in 2014, grossing $773 million worldwide. Whereas superheroes Batman and Superman are burdened with heavy missions on their broad shoulders, Pratt’s Peter Quill/"Star-Lord" just wants to fight villains with his buddies and rock out to his awesome cassette mixes. The gang returns for the sequel, and brooding tree creature Groot (the voice of Vin Diesel) has regenerated himself as a high-pitched, doe-eyed “baby” the size of a branch. In the opening credits, he dances solo to perennial sunny soundtrack hit “Mr. Blue Sky.” The adorable quotient is, yep, sky-high.

Nebula (Karen Gillan)Capital Pictures

Baby Groot’s moves soon give way to a clumsy, unfocused narrative. Here goes: The mercenaries, now in great demand, are recruited by gold-skinned high priestess Ayesha (Elizabeth Debicki) to face off against a space octopus. Mission accomplished. But then Rocket the talking raccoon (the voice of Bradley Cooper) steals the batteries he’s supposed to protect. Furious, Ayesha sends a fleet of ships after the Guardians, which results in a space battle. Which results in a crash landing. Which results in Quill meeting his biological father, Ego (Kurt Russell). Ego is also a planet able to take on human form, both on Earth and beyond. He’s spent decades looking for his long-lost son … though perhaps his intentions are not as sincere as they appear to be.

In other news,
Sylvester Stallone is kicking around. His character shall remain a secret to
uphold the sanctity of a spoiler-free zone. (Well, that and his involvement is too confusing
to properly explain.)

Tangling with costumed villains on some forest planet is not any more ridiculous than what transpired in the origin story. The entire nature of the franchise is ridiculous! Even in a topsy-turvy CGI universe, a wisecracking raccoon has no business allying with green-face aliens, a weird tree thing and the fourth-billed star from Parks & Recreation to fight goons in outer space. But Guardians of the Galaxy worked because it was infused with a surprising shaggy sense of humor and a retro soundtrack.

For the sequel, writer-director James Gunn has doubled down on all these extras. Liked the cheeseball tunes? Looking Glass’ yacht rock hit “Brandy (You’re a Fine Girl)” gets airplay as well as a full-blown lyric dissection. How about the post–closing credits tag? There are about five of them. Child-of-the-'80s Quill also amps up the pop culture references — in one riff, he compares his love-hate relationship with Zoe Saldana’s Gamora with that of Sam and Diane on Cheers. On the second go-round, the amusing special effect no longer seems as special.

Gamora (Zoe Saldana)Capital Pictures

Strip away the once-nifty novelties and what remains is a bloated semi-mess. Despite two uses of the Fleetwood Mac hit “The Chain” — “You will never break, never break the chain” — the Guardians are split in two for long stretches. Pratt is off screen for what seems like an eternity while Michael Rooker's Yondu and Rocket figure out how to spring out of jail on another planet. If Gunn were searching for a spot to cut down from the 125-minute run time, he could have started with Baby Groot dawdling around trying to help them. (Small things should come in small doses.) When the leading man does return, he’s forced to emote. It’s just not a natural state of being for this national comic treasure.

As with all hyped-up sequels, disappointment is written in the stars. But that’s not to say excited audiences desperate for escapism won’t lap up the film’s inherent joyfulness. A lazy weekend screening might do a world of good.